The present invention relates generally to power tools employing batteries to power various tool functions, and more specifically to a battery for such a tool.
A preferred type of tool suitable with the present invention is portable, such as a combustion-powered fastener driving tool, also commonly referred to as a combustion tool or combustion nailer. Tools of this kind are manufactured by Illinois Tool Works, Inc. of Glenview, Ill. and are described in commonly assigned patents U.S. Pat. Nos. 4,522,162; 4,483,473; 4,483,474; 4,403,722 and 6,176,412, all of which are incorporated by reference herein.
Generally, such combustion tools incorporate a housing enclosing a small internal combustion engine. The engine is powered by a canister of pressurized fuel gas, also called a fuel cell. A powerful, battery-powered electronic power distribution unit produces the spark for ignition, and a fan located in the combustion chamber provides both an efficient combustion within the chamber, and facilitates scavenging, including the exhaust of combustion by-products. The engine includes a reciprocating piston with an elongate, rigid driver blade disposed within a cylinder. Such tools include electronic control systems, spark generators, electric fan motors, and other electronic components, and are powered by batteries.
Conventional power tool batteries are preferably rechargeable and are configured for releasably locking into place when electronically connected to a corresponding power tool. This locking engagement facilitates operation of the tool when subject to environmental stress and operational shock impacts that potentially cause disconnection and/or power disruption. Thus, one design criteria of such batteries is the ability to maintain the electrical connection while withstanding environmental stress and operational shock impact forces to which such tools are exposed.
To address this design objective, conventional batteries include a latch element releasably engaging a corresponding opening in the tool, locking the battery in place. An actuator button is associated with the latch for removing the battery from the tool. The latch element and the actuator button are disposed in close proximity to each other so that when the actuator button is depressed, the latch element also moves in the same direction. When the actuator button is sufficiently depressed, the latch element disengages from a corresponding latch-receiving opening in the tool housing, releasing the battery.
In some cases and with some users, it has been difficult for users to depress the actuator button for releasing the battery. Thus, another design criteria for such batteries is ease of actuation.